When referring to a data connection, bandwidth, communication speed, or connection speed is the total maximum transfer rate of a network cable or device. Essentially, it is a measurement of how fast data can be sent over a wired or wireless connection, usually measure in bits per second.
For example, when you connect to the Internet using a modem over a phone line, your operating system may display "Connected at 56 kbps." meaning a maximum of 56 kilobits of data is transferred every second. The more bandwidth a computer has, the faster it will be able to send and receive information. Users with a broadband connection, more specifically fiber optic broadband, can get transfers speeds of up to 10 Gbps, which is nearly 180,000 times faster than a 56kbps modem!
Upload and download
Most broadband connections are asynchronous, which means there are different speeds depending on the way data is traveling. A download speed or receiving speed is how fast your computer can get files from the Internet. The upload speed or sending speed is how fast your computer can send files to the Internet. Download speeds are nearly always faster than upload speeds with these connections.
Note: If bandwidth is shared with other computer, neighbors, devices, etc. you will not reach the maximum capacity reported by your ISP.